Plaintiff administrator in each case alleged that the defendant’s intestate Thomas was negligent in the operation of the automobile in causing the automobile to leave the road and “drove the said automobile into the right-hand temporary bridge railing and into the mill pond whereby the automobile was totally submerged in water and plaintiff’s intestate was killed.” The plaintiff administrator invoked the evidentiary doctrine of res ipsa loquitur to support this allegation. The plaintiff administrator also alleged that the defendant Dickerson, Inc., was negligent in the construction of the temporary bridge and railing and that the negligence of Dickerson, Inc., “concurred and combined” with the negligence of Thomas to proximately cause injury to the plaintiff’s intestates. Plaintiff administrator took a voluntary nonsuit as to defendant Dickerson, Inc.', and the case was sent to the jury as to the negligence of defendant’s intestate, Thomas.
The doctrine of res ipsa loquitur is an evidentiary rule which is expressed as follows:
“ ‘When a thing which causes injury is shown to be under the management of the defendant, and the accident is such as in the ordinary course of things does not happen if those who have the control of it use the proper care, it furnishes evidence, in the absence of explanation by the defendant, that the accident arose from want of care.’ When this combination of circumstances exists it is said that .res ipsa loquitur — the thing speaks for itself.” Stansbury, N.C. Evidence 2d, § 227.
It has been held by our court in Greene v. Nichols, 274 N.C. 18, 161 S.E. 2d 521 (1968), that when an automobile leaves the road for unexplained reasons, the doctrine of res ipsa loquitur arises so as to create a prima facie case of negligence against the driver of the automobile. See also Cherry v. Smallwood, 7 N.C. App. 56, 171 S.E. 2d 83 (1970).
 To invoke the doctrine, a plaintiff must show that the instrumentality was in the exclusive control of the defendant and that the accident is such as does not occur in the ordinary course of things if the person having control of the instrumentality uses proper care. O’Quinn v. Southard, 269 N.C. 385, 152 S.E. 2d 538 (1967).
 In the trial of the. case the plaintiff administrator offered no evidence as to the negligent construction of the temporary bridge railing and took a voluntary nonsuit as to defendant Dickerson, Inc. The evidence in the - case' demonstrated that .the inference could be drawn that the deaths of plaintiff’s intestates .were proximately *509caused by the negligent operation of the automobile by Thomas. The identity of the driver of a vehicle may be established by circumstantial evidence. Greene v. Nichols, supra.
In the application of the doctrine of res ipsa loquitur, it is not necessary that the plaintiff show conclusively that driver negligence was the sole proximate cause of the injury. Greene v. Nichols, supra. Plaintiff administrator alleged that driver negligence was a proximate cause of the deaths of his intestates. The evidence offered demonstrated that this conclusion could reasonably be drawn. It is clear in this case that the negligence, if any, of defendant Dickerson, Inc., in constructing the bridge and railing, did not cause the car operated by Thomas to run off the “thread of the road.”
“If a person’s negligence is in any degree a proximate cause of the injury, he may be held liable, since he may be exonerated from liability only if the total proximate cause of the injury is attributable to another or others.” 6 Strong, N.C. Index 2d, Negligence, § 10.
 The evidence, taken in the light most favorable to plaintiff, shows that the exclusive control of the car was in defendant’s intestate Thomas and that the car ran off the road through the guard rail and into the pond. This is not a normal occurrence without negligence on the part of the driver. The doctrine of res ipsa loquitur properly applies.
. In this case the defendant administratrix contends that the evidence of plaintiff administrator was conflicting as to whether there was ice or frost on the bridge. There was no evidence presented in this case as to whether there was ice on the bridge at the time the car.ran off the road into the mill pond. There was no evidence as to skidding, and the general condition of the road is unknown. There was evidence that sometime prior to the occurrence the roadway was dry. There is no merit in defendant administratrix’s contention. See Cherry v. Smallwood, supra.
We have reviewed all other assignments of error set forth by defendant administratrix and find no merit in them.
MoeRis and Graham, JJ., concur.